Cellular Communication Signals Quiz

• Receptors have intracellular regions that interact with effectors, and can be located on the cell surface or intracellularly.

• Two types of extracellular signal molecules exist: large, hydrophilic molecules that cannot cross the plasma membrane and require receptors on the surface of target cells, and small, hydrophobic molecules that can pass through the plasma membrane and bind to intracellular receptor proteins.

• Examples of ligands include dissolved gases, amino acids, and fatty acids.

• Signal transduction is the process whereby one type of signal is converted to another within a cell.

• Receptor proteins contain at least one binding site for ligands, and a ligand can either activate (agonist) or repress (antagonist) a physiological response.

• Receptors communicate the binding of a ligand to the cell and initiate cell signaling.

• Signal transduction involves the activation of intracellular mediators, which transmit the signal to effector enzymes that bring about changes.

• Secondary messengers alter metabolism or affect effector enzymes that activate target proteins, altering gene transcription.

• There are three types of receptors: ligand-gated ion channels, G protein-coupled receptors, and receptor tyrosine kinases (RTKs).

• RTKs are transmembrane receptors with an extracellular part where ligands bind, a transmembrane domain, and an intracellular kinase domain.

• RTKs phosphorylate tyrosine residues using ATP, adding phosphate groups to specific amino acids.

• Phosphorylation can activate or deactivate proteins and is reversible through phosphatases.

• RTKs can also use monomeric GTPases as molecular switches, with activated GTPases relaying signals further.

• Accessory proteins are needed for the GTPase cycle to take place.

• Phosphorylation and GTP binding act as molecular switches and both need to be turned off.

• The MAPK pathway is a signaling pathway in which a ligand activates the receptor, initiating a cascade of phosphorylations that transmit the signal downstream and activate target proteins.

• Signal termination is necessary to prevent prolonged stimulation, damage, or cell death, and can occur through endocytosis, downregulation, inactivation, or production of inhibitory proteins.

• Some receptors can bind more than one ligand or vice versa, and each cell responds to a limited set of extracellular signals.

• Receptors have intracellular regions that interact with effectors, and can be located on the cell surface or intracellularly.

• Two types of extracellular signal molecules exist: large, hydrophilic molecules that cannot cross the plasma membrane and require receptors on the surface of target cells, and small, hydrophobic molecules that can pass through the plasma membrane and bind to intracellular receptor proteins.

• Examples of ligands include dissolved gases, amino acids, and fatty acids.

• Signal transduction is the process whereby one type of signal is converted to another within a cell.

• Receptor proteins contain at least one binding site for ligands, and a ligand can either activate (agonist) or repress (antagonist) a physiological response.

• Receptors communicate the binding of a ligand to the cell and initiate cell signaling.

• Signal transduction involves the activation of intracellular mediators, which transmit the signal to effector enzymes that bring about changes.

• Secondary messengers alter metabolism or affect effector enzymes that activate target proteins, altering gene transcription.

• There are three types of receptors: ligand-gated ion channels, G protein-coupled receptors, and receptor tyrosine kinases (RTKs).

• RTKs are transmembrane receptors with an extracellular part where ligands bind, a transmembrane domain, and an intracellular kinase domain.

• RTKs phosphorylate tyrosine residues using ATP, adding phosphate groups to specific amino acids.

• Phosphorylation can activate or deactivate proteins and is reversible through phosphatases.

• RTKs can also use monomeric GTPases as molecular switches, with activated GTPases relaying signals further.

• Accessory proteins are needed for the GTPase cycle to take place.

• Phosphorylation and GTP binding act as molecular switches and both need to be turned off.

• The MAPK pathway is a signaling pathway in which a ligand activates the receptor, initiating a cascade of phosphorylations that transmit the signal downstream and activate target proteins.

• Signal termination is necessary to prevent prolonged stimulation, damage, or cell death, and can occur through endocytosis, downregulation, inactivation, or production of inhibitory proteins.

• Some receptors can bind more than one ligand or vice versa, and each cell responds to a limited set of extracellular signals.

Test your knowledge about the transmission and reception of cellular signals, as well as the different modes through which cells receive stimuli. Learn about autocrine and paracrine signaling and their relevance in various cellular activities.